Genetic diversity assessment of walnt (Juglans regia L.) varieties from Argentina using SSR markers
Maria Noelia Ulrich, Alejandro Toro, Juan Gabriel Rivas, Ivan Dario Delgado, Antonio Prataviera and Daniela Tosto
Abstract: Walnut is a globally important nut crop in terms of production and consumption. This study assesses the genetic diversity of the walnut germplasm collection from Catamarca, Argentina (including 13 registered cultivars), using Simple Sequence Repeat markers. Results revealed high genetic diversity, with alleles per locus ranging from 2 to 9 (average 4.67), expected heterozygosity between 0.47 and 0.72 (average 0.64), and 100% polymorphic loci. The average polymorphism information content (PIC) was 0.580, and the mean Shannon’s index (I) value was 1.19. Cluster analysis using Nei´s distances and Bayesian STRUCTURE approximation were consistent with the walnut varietal pedigree. This pioneering study in Argentina offers valuable insights for walnut conservation and breeding programs. It underscores the genetic richness of local walnut germplasm in Catamarca, highlighting its potential to enhance diversification and improvement of walnut production in Argentina.